Put two IP addresses on one NIC

Here is how to have two IPs using one network card in linux.


In the directory /etc/sysconfig/networking/devices

Create the following new file by typing "vi ifcfg-eth0:0"

DEVICE=eth0:0
BOOTPROTO=none
IPADDR=192.168.1.23 # your second IP
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
TYPE=Ethernet
ONPARENT=yes

Next, in the directory /etc/sysconfig/networking/profiles/default

create the same file again by typing "vi ifcfg-eth0:0"

DEVICE=eth0:0
BOOTPROTO=none
IPADDR=192.168.1.14 # your second IP
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
TYPE=Ethernet
ONPARENT=yes


now, bounce networking with "service networking restart" and use ifconfig to see if the net interface shows up...

[root@mail default]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:13:72:52:3A:2C
inet addr:192.168.1.23 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:211994158 errors:2 dropped:0 overruns:0 frame:1
TX packets:1031665949 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:898868933 (857.2 MiB) TX bytes:245145424 (233.7 MiB)
Base address:0xecc0 Memory:fe6e0000-fe700000

eth0:0 Link encap:Ethernet HWaddr 00:13:72:52:3A:2C
inet addr:192.168.1.14 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Base address:0xecc0 Memory:fe6e0000-fe700000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:45061099 errors:0 dropped:0 overruns:0 frame:0
TX packets:45061099 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3353720043 (3.1 GiB) TX bytes:3353720043 (3.1 GiB)